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JOHN BERMAN, CNN ANCHOR: Thanks for joining us at this hour. I'm John Berman. "Legal View" with Ashleigh Banfield starts right now.

ASHLEIGH BANFIELD, CNN ANCHOR: Two big stories happening at this hour. A mass stabbing at a high school near Pittsburgh. At least 20 people, almost all of them kids, hurt. Some of them so badly they're airlifted to hospitals with life threatening injuries. One suspect, 16 years old, in custody. And a community is in shock.

Also, just when all hope of finding Flight 370's fading pings seemed lost, the biggest breakthrough yet in the search. After days of silence, new pings, new hope.

I want to go live right away to the school superintendent who is speaking live. This is Dr. Gernaro Perino (ph) speaking about the incident this morning.

UNIDENTIFIED MALE: Our school community experienced a terrible tragedy. The actions and response of our staff, students and local law enforcement officers saved many lives. Our emergency responders provided critical support and medical assistance. We will continue to work in cooperation with the local law enforcement in the coming days and weeks ahead.

Our high school, as Mr. Stevens (ph) noted, will be closed over the next several days. However, our elementary schools and our middle school will remain open tomorrow, as we know that our school family and system can provide strength and support to our students.

Counseling services will be available for the entire school community. If parents elect to keep their students home, we understand and we will provide any support for those families as well. Further information in regard to these services will be shared out soon.

We appreciate the thoughts, prayers and support from our local community, as well as from across the nation. Thank you.

UNIDENTIFIED MALE: Thank you, superintendent.

Just following up, we do have a very large law enforcement presence. We have assistance from not only local law enforcement here in the Murrysville/Penn Township and surrounding communities. State police are here to assist us with the investigation. The FBI has brought in some individuals to help us with the investigation, background, and trying to see if there was anything that might have led to this particular situation.

At this point, I'll open it up to some questions.

UNIDENTIFIED FEMALE: Could the superintendent tell us a little bit about the principal (INAUDIBLE)?

UNIDENTIFIED MALE: That information will come out at a future time. We're still -- the actual principal that tackled the individual is still being questioned by law enforcement and that information will come out later on.

UNIDENTIFIED FEMALE: What's his name?

UNIDENTIFIED MALE: I can't release that at this point, no.

UNIDENTIFIED MALE: Can the superintendent tell us when the last time there was a drill, any kind of safety exercise here at the school?

UNIDENTIFIED MALE: It was probably - I mean we - you know, that's the one thing that we're very fortunate here. We work very closely -- the Department of Public Safety works with the school district. I know we were just up here probably three months ago for a tabletop exercise and we had a full-scale exercise here about a year ago.

So, you know, Franklin Regional School District has been proactive when it comes to any type of school incidents that occur. And, you know, these plans are reviewed and the plan will be reviewed after this situation to see if anything needs to be improved upon.

You know, we have to look at it from the standpoint that what we saw happen here today was very good evidence that the plan does work and the students are, you know, safe as safe can be. We haven't lost a life. And I think that's what we have to keep in mind.

Remember, we have to keep the people that are affected by this, the 19 students and the one faculty member that was involved in the actual stabbings, we want to make sure that our thoughts go out to those people. It's their world that we have to worry about now. The school will resume and we will be back as strong as we were in the past, if not stronger in the future. Thank you for everyone.

BANFIELD: Just watching this news conference wrap up. This was very brief and very little information as well. Our signal coming to us courtesy of our affiliate in the Pennsylvania area.

Just to summarize quickly, not a lot of new facts on this, but effectively the high school that was affected by this is closed for the next several days. Some of the elementary schools will not be closed at this time, but there will be counseling available district- wide.

One of the key notes made by the official with the emergency management for Westmoreland County said that it is -- it must be said that we have not lost a life and that the emergency and safety procedures that were in place effectively worked despite the carnage, despite the story that you're hearing, despite the pictures on your screen.

This could have been so much worse. Many of the doctors also who have reported live this morning, they do not expect anyone to die, despite the fact that there were several critical and life-threatening injuries that came in to the various hospitals in the Murrysville, Pennsylvania, area.

So, to recap, at least 20 people, most of them kids, wounded at a high school stabbing in suburban Pittsburgh. Several with life-threatening injuries. Four victims so badly hurt they were airlifted to the nearby hospitals. An adult security guard working at the school was one of those stabbed. Stabbed in the stomach, in fact.

The suspect, the person allegedly behind all of this carnage, a kid himself, a male sophomore at the school. And that young man was cuffed on the scene and is now in custody, also injured himself. The police say he was actually flashing two knives as he made his way down the hallway of the school.

All of this unfolding just after 7:00 this morning. Before the first classes could even get underway at Franklin Regional High School in Murrysville, Pennsylvania. It's about 15 miles east of downtown Pittsburgh. I want to let you hear some audio of the police responding to the scene.

UNIDENTIFIED MALE: (INAUDIBLE) come in the front doors. The first hallway on the right, halfway down. We've got multiple victims here. We need ambulances here as soon as possible. Be advised, the suspect is in custody. Only one suspect.

(END VIDEO CLIP)

BANFIELD: Surprisingly, this happened very quickly despite the amount -- the sheer numbers of those who were injured.

And joining me now on the telephone is Mark Dreer (ph). He's the vice president of the security company that actually supplies the security guards to the school.

Mr. Dreer, could you give me an update on the security guard who was one of the injured? The only adult among the injured, we're told.

MARK DREER (ph): Yes. I have not spoke with him directly, but I spoke with the other officer involved. And from what I understand, he's going to be OK. He did get stabbed, from what I understand, in the stomach, rib cage area. But from what I understand, he is going to be OK.

BANFIELD: And if I understood an earlier report that you were able to give live on television here on CNN, he was one of perhaps two school security guards who were involved in the takedown of this young suspect?

DREER: That's what I understand, yes. From my understanding, one of our officers was outside doing parking lot duty. The other two officers were inside. And some of the kids came running out and informed the officer outside what had happened. So that officer went back into the building. And when he did, he was able to observe the security officer that got injured, along with a staff member, trying to subdue the suspect. He ran over and assisted them and were able to, fortunately, get the weapons off of the suspect. But unfortunately at this time is when one of the security officers did get stabbed.

BANFIELD: Do you have any idea, other than just this very generic description of who knives, what kind of knives these were?

DREER: I do not. I can't help you there. I do not. I just know that there were two knives involved.

BANFIELD: And, obviously, at this time of the morning, you know, all the kids are milling about hallways, the parking lot, you know, the -- there's no organization to the kids at that hour. How did the security guards even know what was going on in the hallway? How were they notified?

DREER: From what I understand, and again I'm not certain on this, but from what I understand the fire alarm went off so then all the kids started coming out. And then right where our officers were stationed is where they were able to observe the suspect. So it just so happened that our officer was right there when it happened.

BANFIELD: And is your officer still in the hospital right now?

DREER: From what I understand, yes, he is. But as of today (ph), I've not spoke with him directly. I've been unable to contact him directly.

BANFIELD: OK. There are two competing reports. And understandably there is a lot of confusion right now and there are a lot of injured parties that were taken to various hospitals. But there is one hospital that's actually reporting that an adult who was treated -- it's Forbes Hospital. Their official said one of the adults that was treated was not treated for anything other than a medical condition, not a stabbing, not a knife wound, nothing surgical in nature. Do you know if your other security guards are all OK? Did anybody suffer a medical condition, a heart condition, or anything of that nature that you know of?

DREER: My other security officers are OK. I spoke with them. I'm not sure who the other staff member is. I saw that report, but I am not sure who that person is.

BANFIELD: OK. And we don't know that it's a staff member. We do know this though, that the high school principal was involved as well in this takedown in subduing this 16-year-old sophomore, and that the school resource officer, who is also a police officer, and is at that school daily, was the person who put the cuffs on that teenager and ultimately ended this stabbing rampage.

So there's - and neither of those two was injured according to the police chief who gave an impromptu interview. But he was quite adamant that both of those two parties, the principal and the school resource officer, so integral in stopping this awful, awful attack, neither one of those two was injured. So it remains to be seen who this other adult that the Forbes medical officials were referring to as having a medical condition because of all this and having been treated, it remains to be seen who he is.

Can I just ask you, Mr. Dreer, did -- when you were able to confer with your officers and with those in your company, and, again, your company supplies the security officers to the school, did anyone hear anything from this teenager? Did he say anything as this attack was happening allegedly, if he were the perpetrator, but also after he was subdued?

DREER: Not that I am aware of. When I spoke with my officer earlier, it was shortly after the incident that -- it was a very quick conversation. I was just seeing if he was OK. So I did not get into any of the details. And I have not spoke with him since then, but I will be talking with him later on this afternoon.

BANFIELD: Have you had a chance to talk to his family yet?

DREER: I have not, no.

BANFIELD: Well, listen, Mr. Dreer, thank you very much. We appreciate you joining us with these details.

You know, there are so many details yet to be uncovered in what happened and what possibly could have been the motive for an alleged attack from the hands of a 16-year-old student before classes even got underway at Franklin Regional Senior High School.

Joining me now is Jean Casarez, our legal correspondent, who's also following this story for us.

Possibly the worst time for this kind of thing to happen, because no one is behind closed doors and really able to protect themselves against this kind of attack.

JEAN CASAREZ, CNN CORRESPONDENT: And so vulnerable of a time -

BANFIELD: Yes.

CASAREZ: Right when you're waking up. You're just getting to school. You know, we are learning that the FBI is assisting in this investigation. They're not the primary agency because that is local police, but they are investigating.

We're also learning that when law enforcement first arrived on the scene, what they found were multiple victims just all over the first floor hallway. And we do here, Ashleigh, that there seems to be a pattern in the stabbings of the most serious victims to the right lower abdomen, which is where very, very important organs in our body are. And those are the victims we're hearing are in critical and continue to be in critical condition.

BANFIELD: Shockingly, as well, Jean, the doctor said that every single one of the kids stabbed was stabbed in the torso. There was no accidentally slashing. They were all penetrating wounds.

CASAREZ: And that shows a state of mind right there. Not only the front, to the chest, lower abdomen, but also the back, Ashleigh. And we're hearing that the sophomore that is in custody, 16 years old, a student at that high school, had wounds himself on his hands. So what does that tell you about the violent situation of others trying to get that knife away from him?

BANFIELD: With your legal background, as an attorney and also someone who has covered so many of these cases, what is this young man going through right now? Mental evaluations? Is it arrest, booking, fingerprinting, photographing? Are his parents nearby? Is he being interrogated? What's the process for the kid?

CASAREZ: We had heard early on today that he was being questioned by authorities. Now, that may cease rather quickly when he gets a lawyer. We don't know how much he said at that point. Obviously, his parents should be in the area.

But I was looking up attempted murder in the state of Pennsylvania. Obviously, it is the second most serious felony in the state of Pennsylvania, the first being murder. So there are multiple counts here. They may not all be attempted murder. But there are felonies here and this is going to be a prosecution we'll see in juvenile court or adult court.

BANFIELD: Yes, you know what, that is the next big question -

CASAREZ: Yes.

BANFIELD: Will that assailant be elevated to the most serious court and possibly end up spending the rest of his life in prison for something like this.

Jean Casarez, stand by if you will, please.

On the line, just after the break, we are going to be joined by one of the doctors who treated some of the patients who were brought in en masse to these local hospitals. And some of the stories these doctors themselves are telling, just chilling, like one saying that he recognizes the patients because this is a small community, that he actually treats their parents. That story's next.

(COMMERCIAL BREAK)

BANFIELD: There are 19 families of students today who got the kind of news no one wants to get. There has been an attack at your child's school, and there are some of the grown-ups responding to this horrible news that began unfolding in Westmoreland County, Pennsylvania, just after 7:00 this morning.

A 16-year-old armed with two knives, quote, "slashing them down the hallway," attacked and stabbed, not slashed, stabbed, 19 students, all of them between the ages of 14 and 17, also stabbing a school security guard, who was trying to stop the carnage.

Effectively, the principal of that school is a hero today, the school resource officer also a hero today, because those two adults were able to subdue this assailant, cuff the assailant.

That assailant is also injured, is being treated at a local hospital and, undoubtedly, will be facing some of the most serious charges, whether it's in juvenile court or adult court remains to be seen. But there was the scene outside of Franklin Regional Senior High School.

Many of the hospitals in the surrounding area were put on emergency notice. Get ready, there are multiple injuries and they are coming your way.

One of those doctors, Dr. Timothy VanFleet, the chief of emergency medicine at University of Pittsburgh Medical Center, himself treated six of these patients. He joins me live now. Doctor, can you hear me?

BANFIELD: Doctor, can you just run down what happened from your perspective this morning?

VANFLEET (via telephone): Well, I know just what you have told people basically, that there was a student who had two knifes and apparently was running down the hall of the school just before started, stabbing multiple children.

BANFIELD: And those who arrived at your medical center, and correct me if I'm wrong, it comprises four hospitals, the Presbyterian, the children, the mercy and then the university of Pittsburgh east.

VANFLEET (via telephone): Right.

BANFIELD: Of those who arrived, how many of them were in the most critical condition?

VANFLEET (via telephone): Well, there were basically two in critical condition and two in serious condition. And then eight others that were in lesser -- severely injured.

BANFIELD: How are they all doing right now, do you know?

VANFLEET (via telephone): Well, six have been -- at least six have been treated and released already.

And there's, you know, Children's Hospital of UPMC, there's one in the intensive care unit there and at UPMC Presbyterian, there's one in intensive care there.

BANFIELD: So two now are in intensive care. Any idea on how serious their condition is at this time?

VANFLEET (via telephone): I don't have specific details on that.

BANFIELD: When you were treating the six patients you treated, how serious were those injures? What were those injuries like?

VANFLEET (via telephone): They were all knife wounds obviously. One, the most serious one we received, was actually an arm injury, but it appeared to have a vascular injury with significant bleeding, and that was transferred to children's hospital for surgery.

The others all had various degrees s laceration, to their chest, abdomen, extremities, all of which were eventually treated and released.

BANFIELD: These are kids. These are kids from 14 years old to 17 years old. How were they doing? Were they talking about what happened?

VANFLEET (via telephone): Surprisingly, they were mostly doing fairly well. They of course were scared and anxious. Bu but, you know, otherwise were doing very well.

BANFIELD: Were their parents on the scene right away, were they at the hospital?

VANFLEET (via telephone): Yes, there were parents. Actually, the parents were more upset even than the children as you can imagine because they only heard the news initially and didn't know how sick their children were. So there were lots of distraught families.

BANFIELD: I cannot even begin to imagine the confusion and the chaos among the parents arriving at the hospital, wanting to know -- you know, this could have been so much worse, had this assailant been armed with a gun, God forbid.

But did those kids -- at least the kids you came into contact with, did they say anything about what transpired in that school?

VANFLEET (via telephone): Actually, most of them didn't realize what was happening. They just felt pain and started -- noticed they were bleeding. They said almost all of them said they didn't see anyone coming at them. Apparently, it was a crowded hallway, and they were going about their business and then just felt pain and started bleeding.

BANFIELD: And ultimately didn't even get a look at any point at their attacker before or after they were stabbed?

VANFLEET (via telephone): The patients I treated did not actually see who was doing this.

BANFIELD: At any point, were not able to --

VANFLEET (via telephone): Yes, none of them said they could identify who it was.

BANFIELD: That is remarkable. Did any of the children -- did any of them have a different experience? Did they see the person? Would they be able to identify him?

VANFLEET (via telephone): None -- none of the ones I treated did, no.

BANFIELD: Just unbelievable. How were you all as a hospital community in getting ready for the onslaught of, you know, over a dozen children that were coming to your hospital this morning?

VANFLEET (via telephone): Well, we're fortunate in that we have a lot of good emergency medical services in this part of the state, as well as helicopter transport and a number of good hospitals. So, you know, the calls went out and, you know, the command post was set up and patients were divvied out to a variety of different hospitals so that none were completely overwhelmed.

BANFIELD: I was listening to another doctor who was on staff as well, at Forbes, and he mentioned that he's an obstetrician and that this is such a small close-knit community that some of the children that were coming in were actually the children of moms who were his patients.

And he was really overwhelmed and overcome with emotion as he was trying to answer reporter's questions. He said, you don't understand what it's like when you know the victims coming in. Did you have that similar experience?

VANFLEET (via telephone): No, it is, you know, it is a small community and people are known but I didn't know any of the kids that I took care of personally.

BANFIELD: And once again, I just want to reiterate for those who might be just joining us, Dr. VanFleet, how are all of the kids that came into your hospital system?

VANFLEET (via telephone): How are they?

BANFIELD: Yes, how are they right now and how are they going to be?

VANFLEET (via telephone): I think, as best I know, I think they'll all survive but there are still four that are in very critical and serious condition. At two different facilities and, you know, time will tell.

BANFIELD: Four in critical and serious condition, one of them in intensive care at the children's hospital, I think as you said, and another one in the intensive care at -- what was the second hospital?

VANFLEET (via telephone): Presbyterian Hospital.

BANFIELD: Presbyterian. Obviously, our thoughts and prayers are with them for a speedy recovery. Thank you not only for your time right now but for the work you did in making sure that this wasn't a worse scenario. Dr. VanFleet, thank you.

VANFLEET (via telephone): Sure, you're welcome.

BANFIELD: Dr. VanFleet joining us. He's the chief of emergency medicine at the university of Pittsburgh medical center east. We're continuing to watch this story to find out not only what happens to the perpetrator in this crime -- because one of those who's being treated, we're told from the police chief, is the perpetrator himself. He suffered injuries to his hands.

Whether he's included in that 19 count or not, I can't tell you that, but 19 kids being treated for stabbing injuries in this community and one adult at this point being treated for a stabbing injury. At least one other adult could have also been treated for a medical condition. All sort of parceled up within this incident that took place.

We're following big new developments in another story, as well, the search for Malaysia Airlines Flight 370. Two new sets of pings have been detected. That is prompting some very powerful and hopeful words from the man who may know best, the head of the entire search operation.

We'll tell you what he's saying. We'll tell you what they're doing. We'll tell you just how good this is for those who are involved.